The present invention relates to a heating apparatus of the type wherein the weight of a foodstuff to be heated is measured to control the apparatus.
It is known to automatically control a heating apparatus such as microwave ovens in accordance with the weight of a foodstuff being cooked as shown and described in Japanese Patent Publication No. 58-160742. The weight detector disclosed in this publication is of the type wherein the placement of a foodstuff on a table causes it to vibrate at a frequency determined by the weight of the foodstuff and this frequency is detected as a measure of the weight of the foodstuff. Since the vibration of the table diminishes to an insignificant level with time, it is necessary to effect the weight determination at the instant the foodstuff is placed on the table. However, undesirable oscillations may occur during the initial period and would result in an error in the weight determined. Furthermore, foodstuffs may be placed in succession before the door is closed. This would need to continuously monitor changes in the weight of the foodstuff before the door is closed.